1. Field of the Invention
This invention relates generally to the handling of containerized cargo and, more particularly, has reference to a new and improved safety cage used by workers who are attending to the locks on stacks of cargo containers.
2. Description of the Prior Art
Many modern cargo ships carry their loads in large rectangular boxes called containers. These containers are made of steel or some other metal material and are strengthened to withstand stacking and motion at sea. They come in a variety of sizes, but a size of 20'L.times.8'W.times.8'H, resembling a large truck van, is considered an industry standard.
The containers are moved about by cranes. Hooks on a bridle suspended by the crane engage eyes in the upper corners of the containers. The crane raises the bridle to hoist the container aloft and move it to a desired location.
The containers are usually stacked one-upon-another and the stacks are placed side-by-side to form rows. Devices called "cones" are used to join and lock the upper corners of adjacent containers and thereby prevent accidental slippage. These cones are placed (for locking) or pulled (for unlocking) by workmen who traverse across the tops of the stacks.
The safety of the workmen attending to the locks is a matter of paramount concern. An ideal safety device would provide effective protection for the workmen, would be convenient and efficient to use, and would be compatible with existing cargo handling procedures and equipment. The various devices currently proposed by others are unsatisfactory in one or more respects. The present invention fulfills all of those needs.